A Juárez police officer has been arrested in connection with the death of a teenager found in a vacant lot in Juárez last week, the Chihuahua attorney general's office said.

State investigators arrested Eduardo Sotelo Guerra, 25, on Saturday on a homicide charge in connection with the death of Mario Alejandro Perez Rivera, 17, who was found Thursday morning in a vacant lot at Federico de la Vega and Solis Barrera streets in southeast Juárez, officials said.

The attorney general's office said that Sotelo allegedly told investigators that his rifle accidentally fired when he dropped it during a chase and that he didn't know that he had shot anyone.

After Perez was found dead, his friends and relatives told investigators that Perez had been attacked by police, the attorney general's office said in a news release. Investigators found Sotelo by checking police work logs to find who had patrolled that district.

The attorney general's office said that Sotelo told investigators that he was on patrol when he was flagged down by a woman who reported that three people, who appeared to be gang members and suspects in robberies in the Parajes de San Isidro area, were hanging out in a vacant lot.

According to the attorney general's office, Sotelo said that the men began to run when he arrived at the vacant lot. While getting out of his patrol vehicle, Sotelo told investigators that his rifle fell and accidentally fired and he didn't know anyone was shot. Sotelo then continued on his patrols, the attorney general's office said.

The attorney general's office said that Perez was shot in the head and that an analysis determined that the bullet removed during an autopsy was fired from a .223-caliber rifle, such as the one used by Sotelo.

The Norte newspaper reported that Perez was one of at least seven homicides in Juárez in the first four days of October, including the killing of ministerial police Commander Jesus Aleman Alvarez, who was shot to death outside his home Saturday.

Daniel Borunda may be reached at 546-6102; dborunda@elpasotimes.com; @BorundaDaniel on Twitter.